This invention relates to a hook drive for chain stitch sewing machines, in particular.
Chain stitch sewing machines are used for joining together abutting cloth edges in various fields of industrial finishing. Such machines are generally equipped with a movable cutter blade placed in front of a sewing needle to cut a cloth prior to sewing, and are accordingly also known as "cutter" or "overcast" sewing machines.
In a machine of the above general type, the motion of the two hooks follows a rectilinear back-and-forth pattern. This involves disadvantages both of constructional and functional characters. The construction of such machines is bulky and requires a high number of component parts for operating the hooks. This results, in turn, in increased manufacturing costs and a heavier machine. Functionwise, moreover, the reciprocating hooks fall short of providing those movement accelerations and decelerations which would ensure faultless formation of the stitches even at high sewing speeds, as is presently required by the industry.